To their epithelial-like morphology and reduced motility. Besides the recruitment of E-cadherin to the Arr-HSC cell membrane, its expression in these cells was increased when compared to the Ctrl-HSC cells. The amount of E-cadherin mRNA in the Arr-HSC cells was 1.9-fold 60.06, and that of protein 1.6- fold 60.12, both significantly higher than in control cells. Strong immunofluorescence signals for the mesenchymal marker vimentin were observed in some individual Ctrl-HSC and Arr-HSC cells, but evident differences in these signals could not be detected between the cell lines. We next wished to determine the reason underlying the thin top cell layer formed by the Arr-HSC cells in the organotypic model, and set out to study tumor cell proliferation and apoptosis. The number of proliferating Ki-67-positive tumor cells was smaller, but not statistically significant, in the Arr-HSC than in the Ctrl-HSC 3D cultures, which is in agreement with our observation on reduced tumor cell proliferation in Arr-HSC xenografts. The TUNEL assay showed that the Arr-HSC cells underwent apoptosis more often than the control cells in the 3D model. Since the TUNEL assay also detects other types of cell death in addition to apoptosis, we wanted to confirm our finding by caspase-3 staining. We observed a MCE Company 66547-09-9 similar and significant trend on increased apoptosis in Arr-HSC cells although the increase was milder than the one in the TUNEL assay. In HSC-3 xenografts, however, only few TUNEL-positive cells were detected mainly in the keratinized central tumor areas. We have previously shown that recombinant arresten affects mitochondrial apoptosisrelated Bcl-family signaling molecules in microvascular endothelial cells. In the current experiment the pro-apoptotic Bax protein showed 1.9-fold 60.23 increase in the Arr-HSC cells relative to the Ctrl-HSC cells, whereas the anti-apoptotic Bcl-xL protein level 179068-02-1 concomitantly showed a decreased, although not statistically significant, trend to 0.8-fold 60.049 of the controls, thus shifting the balance towards a situation favoring apoptosis. To pursue the mechanisms underlying the altered behavior and morphology of Arr-HSC cells we performed measurements using electric cell-substrate impedance sensing, a method that provides quantitative data on
